Recurrent diving-related inner ear barotrauma.

OBJECTIVE: To present two cases of recurrent diving-related inner ear barotrauma (IEB) and to discuss the possible cause and pathogenesis of the increased inner ear vulnerability. STUDY DESIGN: Case series. SETTING: Tertiary referral center. PATIENTS: Two scuba divers suffering from repeated cochleovestibular barotrauma. INTERVENTIONS: Neurotological evaluation, perilymphatic fistulae repair, and conservative treatment. MAIN OUTCOME MEASURE: The increasing popularity of scuba diving expose the individuals involved in this sport to unique pathologies that are not common under terrestrial conditions. The otolaryngologist who is involved in the care of these patients is required to diagnose and treat diving-related ear injuries and to consider the risk for recurrent inner ear injury when diving is resumed. CONCLUSION: IEB carries a risk for permanent hearing loss and chronic vestibulopathy. We recommend complete neurotological evaluation including high-resolution CT of the temporal bones as a routine workup for IEB. The presence of a significant residual sensorineural hearing loss, evidence for noncompensated vestibular damage, and CT findings of possible enhanced cerebrospinal fluid-perilymph connection should be considered when a return to diving activity is considered.     

Inner ear decompression sickness and inner ear barotrauma in recreational divers: a long-term follow-up

OBJECTIVES/HYPOTHESIS: The objectives were to report the authors' experience with the long-term follow-up of patients with diving-related inner ear decompression sickness and inner ear barotrauma and to discuss residual cochlear and vestibular damage in relation to the question of fitness to dive. STUDY DESIGN: Retrospective consecutive case series. METHODS: Eleven recreational divers with inner ear decompression sickness and nine with inner ear barotrauma (IEB) were followed. A complete otoneurological physical examination and laboratory evaluation were carried out. The latter included audiometry, electronystagmography, a rotatory chair test using the sinusoidal harmonic acceleration protocol, and computerized dynamic posturography. RESULTS: Residual cochleovestibular deficits were found in 10 (91%) of the patients with inner ear decompression sickness and 3 (33%) of those with IEB (P <.02, Fisher's Exact test; odds ratio, 20). A significantly shorter follow-up period was required for the inner ear barotrauma group (P <.05, simple t test) because three patients (33%) recovered completely within 1 month of the diving accident. Eight patients had residual vestibular deficits on follow-up, but only one (12.5%) was symptomatic. However, five (56%) of the nine patients who had a cochlear insult, as documented by follow-up audiometry, complained of significant hearing loss and tinnitus. CONCLUSION: Inner ear decompression sickness carries a high risk for residual inner ear damage despite hyperbaric oxygen recompression therapy. A favorable prognosis might be anticipated for inner ear barotrauma. The finding that most patients with residual vestibular deficits were asymptomatic at the time of follow-up emphasizes the need for a complete vestibular evaluation, including specific bedside testing and laboratory examinations, before a return to diving activity may be considered.     

Pharmacological models for inner ear therapy with emphasis on nitric oxide

Nitric oxide (NO)-mediated neurotoxicity may be an appropriate pathophysiological model with which to explain a variety of inner ear diseases characterized by acute or progressive hearing loss, tinnitus and vertigo. The localization of NO synthase (NOS) isoforms was examined in the inner ear of the pigmented guinea pig after intratympanic injection of 1 mg lipopolysaccharide (LPS) or 5 mg gentamicin (GM) using an immunohistochemical method, revealing the expression of NOS II in the inner ear. Production of NO in the isolated organ of Corti and utricle or in the isolated vestibular and cochlear hair cells after stimulation with L-arginine, glutamate, GM and LPS was investigated using the fluorescence indicator 4,5-diaminofluorescein diacetate. The fluorescence intensity of the sensory cells was augmented by stimulation with L-arginine, glutamate, GM and LPS. A significant increase in NO production was also noted in the LPS-treated animals. These findings imply that NO from constitutive NOS may mediate ototoxicity in the early phase, whereas NO from NOS II may contribute to the late phase of tissue damage in the inner ear. Based on this hypothesis, reduction of glutamatergic excitotoxicity and inhibition of NOS, scavenging superoxide and scavenging peroxynitrite are thought to attenuate NO-mediated otoneurotoxicity.     

Optical coherence tomography imaging of the inner ear: a feasibility study with implications for cochlear implantation

Cochlear implantation is now being performed in ears with residual hearing. Those implant recipients who keep residual hearing may benefit from improved pitch resolution through both electrical and acoustic hearing. Preservation of cochlear function after implantation is a challenging task for the surgeon. Current topics of hearing preservation research include electrode design and surgical technique. To maintain hearing, surgeons strive to create a cochleostomy and place the electrode in a minimally traumatic fashion. In this study, we examine a novel catheter-based real-time imaging modality with 10- to 15-microm resolution, optical coherence tomography (OCT), on the inner ear. We demonstrate the capability of OCT to allow visualization of inner ear structures through bone in live mice. We additionally used OCT to image the inner ear in a human temporal bone. Optical coherence tomography was able to delineate soft tissue structures within the cochlea and may be useful as an adjunct to cochlear implantation. Other potential otologic applications of OCT are discussed.     

Acute low tone sensorineural hearing loss caused by inner ear barotrauma

Three cases of inner ear barotrauma with subjective symptoms and hearing impairment which were similar to the low tone sudden deafness were reported. Case 1 was a 34-year-old man who developed a hearing loss in the next morning of taking an airplane and recovered four days after. Case 2 was a 42-year-old man who developed a hearing loss 2 days after flying in an airplane and hearing loss have recurred 4 times in his right ear for 3 months. Eight months after recovery of previous recurrent attack, a hearing loss occurred in his left ear without flying and recurred twice for 3 weeks. Case 3 was a 25-year-old woman who developed a hearing loss in the right ear after 24 meter depth scuba diving and recurred 4 times for 40 days. Those three patients complained of no vertigo at any attacks and were treated conservatively. From previous reports and the onset and the course of hearing disturbance, acute low tone sensorineural hearing loss in case 1 and case 2 was thought to be caused by circulatory disturbance of the inner ear and in case 3 thought to be caused by inner ear window rupture. But, endolymphatic hydrops was also needed to be take into account in those three cases as a common possible cause. Inner ear barotrauma and so called labyrinthine window rupture were considered to be one of the diseases needed to differentiate from low tone sudden deafness without reference to mono-attack type or recurrent type.     

Recovery and probable persistence of cytomegalovirus in human inner ear fluid without cochlear damage

Cytomegalovirus (CMV) was recovered from a 5-month-old infant with probable congenital infection. In life, no hearing impairment had been observed. Auditory brain stem evoked responses were bilaterally intact. At necropsy, both temporal bones were morphologically normal, as demonstrated by light and electron microscopy. Sensory hair cells of the organ of Corti appeared intact. Cytomegalovirus was recovered from a mixture of perilymph and endolymph, but not the brain, CSF, or vitreous humor. This appears to be the first report of an individual with an inner ear CMV infection in which neither structural nor functional alterations of the inner ear were apparent. This case also suggests that CMV can persist within the inner ear for prolonged periods following congenital infection.     

内耳畸形小儿人工耳蜗植入术后电极阻抗测试的研究

目的探讨内耳畸形小儿人工耳蜗植入手术后,植入体电极阻抗值的变化特点及规律。方法对36例澳大利亚Cochlear Nucleus 24型内耳畸形小儿人工耳蜗植入手术患儿,测试手术中及手术后1年阻抗值,并分析其特点及变化规律。结果患儿术中及开机后1年内高中低频段电极阻抗值变化趋势相同。电极阻抗值术中自开机显著增大,术中阻抗值最低,开机达到最大值,其后呈下降趋势,于开机3月后趋于平稳。结论内耳畸形小儿人工耳蜗植入手术后电极阻抗值开机3个月内变化明显,故需多次调机,以使患者语言感知达到最佳状态。     

Outcomes of cochlear implantation in children with inner ear malformations

European Archives of Oto-Rhino-Laryngology - To evaluate the surgical experience and auditory functions and progress of speech development of cochlear implantation in malformed ears. Between...     

先天性内耳畸形患者多通道人工耳蜗植入的效果观察

目的探讨多通道人工耳蜗在先天性内耳畸形患者植入的效果.方法对16例先天性内耳畸形患者(畸形组,Mondini畸形12例,大前庭导水管综合征4例),2例经前庭窗植入电极,3例经鼓岬植入电极,11例经圆窗龛前上缘植入电极.2例术中发生镫井喷.以10例耳蜗发育正常的植入者作为对照组,进行术后效果对比.结果畸形组与对照组术中和术后并发症差异无显著性意义.术后听阈畸形组多数患者达到30～40 dB HL,与正常组相似,仅少数患者听阈稍高.经统计学分析差异无显著性意义(P>0.05).听觉语言康复效果畸形组多数与对照组接近.结论多通道人工耳蜗植入适用于绝大多数先天性内耳畸形的患者,术后听力及语言康复效果满意.     

内耳发育畸形患者人工耳蜗植入术后的疗效分析

目的分析内耳发育畸形患者行人工耳蜗植入术后的疗效。方法回顾性分析2011年1月~2017年7月在西南医科大学附属医院行人工耳蜗植入术的30例内耳发育畸形患者的临床资料,其中大前庭水管综合征(large vestibular aqueduct syndrome,LVAS) 8例,Mondini畸形（不完全分隔Ⅱ型）7例,同时伴有LVAS和Mondini畸形10例,内听道狭窄5例。随机选取同时期临床资料相匹配的30例耳蜗结构正常的人工耳蜗植入患者作为对照组。采用听觉行为分级标准和言语可懂度分级标准进行评估。比较两组患者的术前听力、术中情况以及术后听觉言语康复情况。结果3例LVAS患者在术中耳蜗钻孔后出现外淋巴液不同程度的外涌,1例Mondini畸形患者术中出现脑脊液井喷现象。两组患者术后均获得有意义的听觉反应,术后的听觉言语能力相比较,差异无统计学意义（P>0.05）。同组患者,术后3,6,9,12个月的听觉言语能力均较各自术前均有明显提高（P<0.05）。结论内耳发育畸形患者不是人工耳蜗植入术的绝对禁忌证,其术后言语康复效果与内耳结构正常者无明显差异,但手术难度比内耳结构正常者要大,术前应根据不同的畸形类型制定个性化的手术方案,以减少并发症的发生。     

Experimental vibratory damage of the inner ear

The aim of the experiment was to determine the effect of whole-body vibration on the inner ear. The investigations were carried out on 40 guinea pigs, subjected to sinusoidal vibration (10 Hz/5 mm/1.4 g rms) for 1 to 6 months in a noiseless apparatus. Cochlear microphonic measurements were done with a phase-sensitive detection technique for the levels 70, 80 and 90 dB and the frequencies of 0.26, 0.5, 1 and 2 kHz from the apex of the cochlea and for 4 and 8 kHz from the region of the round window. Analysis of 1,440 measurements suggested the possibility of damage appearing in the upper turnings of the cochlea. The subsequent morphological analysis was based on the estimation of the state of the hair cells (a three-degree scale of injury) in a Zeiss DSM 950 scanning microscope and of the structure of the fibers of the acoustic nerve in a Zeiss EM 900 transmission microscope. Vibration-induced changes were seen in all the examined inner ears of the experimental groups. Hair-cell damage was more often seen in the region of the apex, spreading gradually in the direction of the base and from the circumference (outer hair cells of the third row) to the modiolus. The most characteristic vibrational changes of the acoustic nerve fibers occurred in 100% of the examined myelin sheaths and were visible as decreases in their electrodensity. The changes in both the assessed elements of the inner ear appeared simultaneously but independently and were directly connected with the duration of the experiment. The results obtained allow an explanation of the mechanism of hearing loss in persons subjected to whole-body vibration. The damages done to the inner ear structures may cause a worsening of hearing there, especially in the low and medium frequencies.     

Middle and inner ear barotrauma caused by scubadiving (author's transl)

On the basis of our own experiences and the current literature, the following guidelines were established for the evaluation of scubadivers: 1. The ENT physical examination must include otoscopy and the valsalva manoeuver. The scubadiver should be able to promptly and symmetrically inflate his middle ear spaces. A central perforation is a relative contraindication, while a marginal ear drum perforation is an absolute contraindication for scubadiving. 2. Recommendations to the diver: Ear pressure equalibration should be performed continuously with increasing and decreasing water depth. Ear plugs should never be used. 3. Management of diving injuries: Barotitis should be treated in a manner similar to acute otitis media. Transient vertigo while ascending (alternobaric vertigo) without nystagmus or hearing impairment needs no further vestibular examination. A middle ear exploration is indicated when there is suspicion of a perilymphatic fistula.     

先天性内耳畸形并中耳畸形患者多通道人工耳蜗植入术3例报告

目的：探讨先天性内耳畸形并中耳畸形患者行多通道人工耳蜗植入术的方法及效果。方法：1995年5月-2002年5月我院为3例罕见的先天性内耳畸形并中耳畸形患者经乳突进路行人工耳蜗植入术,分别植入27、28、32个电极,植入后3个月行声场测听。结果：3例患者均成功地行人工耳蜗植入,术中、术后无严重并发症发生,术后声场测听听阈达35-40dBHL。结论：罕见的先天性内耳畸形并中耳畸形患者也可行人工耳蜗植入术,术后效果满意。